Fracture Mechanics Forum

As I understand it, there are many geometries for which the j-integral has been found to give useful simplifications when evaluating the energy release rate. Many of these geometries seem to require small displacements. I would like to know if the small displacement requirement is necessary for the contour integral before any simplifications are made or if small displacements are only necessary because the large deformation geometry of some specimens conflicts with those simplifications.

For several common electroplated materials: Ni, Cu, Au and Al, which one has strongest fatigue strength? We know the mechanical properties of thin films are different with their bulk counterparts due to the so called "size effect", and material properties depends largely on the microstructure and processing technique. But is there some mateiral laws or guidelines for designers to choose the "best material" as for fatigue resistant? Yield limit? ultimate tensile strength? or elongation? How could one compare material candidates without doing time-consuming test?

hii

I  need a bit help in preparing my seminar topic on the subject "Miniature disk bend testing".If anyone can help me out from this problem i will be indebted for life time.

    You can post me the link, sites, any information on my email  id- bapu285 [at] gmail.com.

waiting for a reply.

please help me out from this problem

Sir,

I am doing my PG in Design Engg. & project is going on. Please tell me where I will get the analytical solution of S.I.F. for a plate with central crack & under tensile loading. please tell me the names & authors of the books.Also if possible derivation of Tada Fedderrson & Irwin formulae.

Thanking you

Hi every one,

    Iam searching for the paper 

    "  charalambides P.G. ,J. Lund, A.G. Evans and R.M. McMeeking(1989),  A test Specimen for determing fracture resistance of     bimaterial interfaces . Journal of Applied mechanics, volume :56, pages 77-82. "

     Iam unable to find this paper. I need this paper for my thesis work. Is there any one find this copy please attach the copy.

Hello,

As far as I understand from the previous blogs: we can now embed XFEM in ABAQUS. Is this approach restricted to linear elastic behavior? Can we simulate fracture propagation in an elasto-plastic material ("XFEM coupled with ABAQUS" type analysis) or is this approach only limited to fracture propagation in elastic materials.

 Thanks,

 Uno.

I am working for the FE model of cracked pipes. I use Hypermesh to mesh the model, but the element can not be set to the C3D20R type. I donnot kwon why it is. So I can use the C3D15. Then I can th following error message:

***NOTE: THE COORDINATES OF NODES WITHIN THE SAME CLUSTER ARE NOT IDENTICAL.  THIS IS THE CASE FOR NODES 22 1224

***ERROR: TRIANGLES, TETRAHEDRA, AND WEDGES MAY NOT BE USED IN A CONTOUR INTEGRAL REGION. ELEMENT 960 IS WITHIN A CONTOUR REGION

I use the chebyshev polynomials to solve the singular integral equation of a crack problem. I encountered a problem that when Chebyshev polynomials are truncated  at the even order, the results are convergent. However, if the polynomials are truncated at the odd order, the results are not convergent. Does anybody have any idea about this?  Thanks a lot.

1. Central crack loaded with stress.

(A) The stress intensity factor for a central line crack in an infinite plate is found to be  

 K=p(πa)^.5

where p is the pressure exerted along the crack line. (A) Does this formula imply a stable or an unstable crack propagation when p reaches the critical stress level? (B)  Present an experiment to support your answer in (A). Specify your experiment in details.